The present invention relates generally to magnetic components for electronic circuits, and more particularly to bobbin and core structures for reducing gap losses in magnetic components such as inductors and transformers.
Conventional magnetic components such as inductors and transformers generally include a bobbin about which one or more conductive windings are placed. One or more magnetically permeable core members are also generally placed on or near the bobbin such that a magnetic field interaction is achieved between the core members and the conductive winding. In many applications, the core members are positioned such that a gap is defined between the core members at a location inside the bobbin structure. Air gaps may be provided for a variety of reasons, such as to influence magnetic or electrical performance of the magnetic component.
One problem associated with bobbin-wound magnetic components having a core air gap is leakage inductance. Leakage inductance results in local stray magnetic flux that may adversely affect performance of the magnetic component. In magnetic components having conventional bobbin and core structure configurations, stray flux associated with leakage inductance across a core air gap may interact with local regions of the conductive coil, leading to undesirable eddy currents. Stray flux interaction with the conductive coil may also cause an undesirable temperature rise in the coil, further reducing performance. Such interactions also cause eddy losses and reduce performance of the component.
Others have attempted to overcome the problems associated with stray flux by changing winding patterns or air gap dimensions, but such approaches are generally inadequate.
What is needed then are improvements in magnetic components and associated bobbin and core structures to reduce gap losses and other undesirable effects associated with stray flux near core air gaps.